Calendering Methods for Various Paper and Board Grades Specialty Papers 6.9.4.3.1 Silicone Base Paper Silicone base papers are used as carrier papers for the later application of a one-sided or two-sided layer of silicone, onto which, in the following operations, fur¬ther layers, e. g. adhesive in combination with label paper, are applied. Silicone base papers [...]

6.9.4.2.2 Woodfree Coated Paper Grades With these papers a differentiation must be made between single-coated, double-coated and triple-coated papers. In addition, it is also of significance whether the papers are to be used in rolls or as cut-size sheets. Single-coated, woodfree papers are generally calendered on-line. The machines used for this are mostly 2 V [...]

The Main Calendering Methods for Various Paper and Board Grades 6.9.4.2.1 Woodfree Uncoated Papers Woodfree uncoated papers include, above all, office papers, which are in turn subdivided into writing and printing papers as well as copy papers. In the past, these papers were not supercalendered. Simple machine calendering was con¬sidered satisfactory. However, the demands made [...]

The Main Calendering Methods for Various Paper and Board Grades 6.9.4.1.4 Blade-coated LWC/Offset and Rotogravure LWC papers are either blade-coated or film-coated. In both cases it is recom¬mended to calender the base paper before coating. The objective of this pre-cal-endering is to optimize the CD caliper profile, to compact the sheet structure and to easily [...]

The Main Calendering Methods for Various Paper and Board Grades 6.9.4.1.2 SC-B/Offset and Rotogravure SC papers can be subdivided into two main grades, SC-B with a high percentage of recovered paper (up to 100 %) and SC-A with a high percentage of woodpulp (TMP or groundwood; up to 80 %). In contrast to SC-A top [...]

The Main Calendering Methods for Various Paper and Board Grades 6.9.4.1 Wood-containing Paper Grades 6.9.4.1.1 Newsprint Newsprint belongs to the group of uncoated, woodcontaining printing papers. Nowadays it consists of up to 100 % DIP (deinked pulp), basis weight around 45gm–2. These papers are produced on machines at speeds of up to about 1900 m [...]

History of Calendering From the very beginning there was a desire to glaze the rough surface of paper. The procedure then was to lay each hand-made sheet on a smooth surface and treat it with an agate or pumice stone. Nothing changed in this tedious procedure for centuries. Later, water-driven hammers came into use for [...]

The Different Calender Types 6.9.3.1 Machine Calenders Machine calenders consist of two or more hard rolls and are practically always installed on-line. They are primarily used for paper that only requires moderate finishing or for pre-calendering grades that need further finishing treatment in order to obtain higher gloss and/or smoothness. Machine calenders are equipped with [...]

Paper Calendering Objective and General Description of the Calendering Process The objective of calendering is to modify the surface characteristics of paper with regard to its further use, e. g. printing. Depending on the individual grades, the focus is put on different technological properties. These are mainly . • gloss . • smoothness/roughness . • [...]